Lake Tahoe Sees Mysterious Loss Of Aquatic Animals And Vegetation

Scientists at the University of Nevada, Reno, are working to figure out why small animals and plants that typically inhabit the bottom of Lake Tahoe are dying off at an accelerated pace, according to the Associated Press. The losses are affecting stoneflies, bottom shrimp and water mites.

Still other animals have been impacted more dramatically, with populations of blind amphipods and the Tahoe flatworm dropping more than 99 percent.

“They are disappearing. It’s unprecedented. It’s absolutely dramatic,” said Sudeep Chandra, associate professor at the university, to the Reno Gazette-Journal.

Lake Tahoe’s Emerald Bay. (Credit: Flickr User the_tahoe_guy via Creative Commons 2.0)

To tackle the issue, dive teams have completed a pass around the entire water body, documenting habitats and organisms. Chandra and others are working to analyze those findings, but the cause of the die-offs remains unclear.

Some hypothesize that impacts to animal populations are largely due to losses that aquatic plants are feeling. These could be due to diminished clarity for the lake overall, as clearness has dropped from 100 feet to a relatively stable 70 feet in the past 55 years. Invasive crayfish in Lake Tahoe, which have populations nearing 300 million, could also be grazing on the aquatic plants.

North Lake Tahoe. (Credit: Wikimedia Commons User WPPilot via Creative Commons 4.0)

The first round of dives was completed at depths of about 15 to 20 feet. Researchers are now hoping to secure funding that would support another series of dives to look into deeper sections of the lake.

“It looks like clarity is beginning to stabilize, but the bottom of the lake continues to change at a dramatic rate,” said Chandra to the Reno Gazette-Journal.